RUG/Pennsylvania/State College/Printers/PSU Fab@Home

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FAB@HOME LOGOPrototype.png


Progress

4/29/2012:
Fab@home is now fully operational in all axes. The next step in its developement will now be to undergo print testing, or alternatively, convert the electronics to RAMPS_1.4 with Marlin Firmware now that all electrical components have been confirmed opperational.

2011:
Pennsylvania State University (PSU) Fab@home is in operational mode and continue to be in diagnostic form. Within next week, we have an idea how to approaching for the future project.

Printer Status

Operating Specifications
Name Status Design Electronics Firmware Extruder Temperature Comments
Fab@Home Purple Working Fab@home LPC-H2148 Microcontroller Model 4 Syringe ??? ???

PSU Fab@Home - Current Condition

Build Notes

The majority of the initial PSU Fab@home build was completed by original owner, before it donated by after prolonged difficulties regarding its operational status. An initial attempt was made to get the Fab@Home to an operational state in 2011, but this only resulted in the movement of several axes.

Having decided to reinvestigate the printer in spring 2012, we were able to drive all axes after much trouble shooting. Problems that were fixed included incorrect wiring from X-axis stepper motor to microcontroller board, a faulty 24V power supply (carefully switched to a 12V for testing purposes), disconnection of endstop ground connections, a missing endstop pullup resistor on the microcontroller, and loose pin to endstop connections.

The only problem that still exists a driver error when the power supply is disconnected before the USB. No advancements were made in the course of our trouble shooting, but this problem seems to be avoidable. Students found that one must simply be careful of the order when disconnecting these cords, and if mistakes are made, a simple restart is all that is necessary to have printer back in working order.

Electronics

We were fortune enough to have all the working electronic kits and installed as instructed. Microcontroller for Fab@home model 1:Microcontroller Olimex Philip LPC-H2148 (under ARM) Apparently, we are missing the JTAG cord which is important for flashing the microcontroller. I believe we are specifically looking for OpenOCD with firmware v4. However, the board were flash for firmware v3. Firmware module

Software

Currently, PSU Fab@home is using Fab@home v.23 made by cornell university and [email protected]


A Fab@home Toolchain.
Fab@home Toolchain.

Fab@home Software: Necessary for operation in stock form.

  • FabStudio: Slicing software that generates .fab files.
  • FabInterpreter: Printer control software. Only capable of printing with .fab files.
  • svg2fab v2.0: Useful for producing 2D .Fab files for toolheads such as vinyl or foam cutters.
  • Fab2GCode: Converts .fab files to .gcode files.




Printable Materials

Currently we have Acrylic Winsor Blue available for part to print. More to come on order and check out vendors for harware and material

MATERIAL TYPES
LINKS
Ultraviolet Curing Materials
Koba UVG-1
Edible Materials
Chocolate, Frosting
Conductive Materials
SS-26 Silver-filled Silicon
Thermosets
FabEpoxy, Silicon


Tools

Syringe Extrusion

Vinyl Cutting Tool

Diagnostic Notes


PROBLEM
SOLUTION
All but 1 endstop reading zero and randomly flucating between 0 and 1.
Missing pullup resistor on microcontroller.
Motors becoming overly hot.
Adjusted the potentiometers so the motors
had just enough power to drive the
axis and run the extruder.
Firmware connection problem.
1. Restart computer. Will happen when unplugging power supply before USB.
2. Reload drivers in computer/properties/hardware/com
Y-axis refusing to drive.
1. Check Y-axis potientiometer
2.Reduce belt tightness.
Significant backlash in lead screws.
Move nut on the end of the lead screw tighter against plexi.


Future Projects

Electronics and Software:

  • Convert electronics to RepRap style electronics and firmware(RAMPS1.4 w/ Marlin firmware). This would allow Fab@home to our ultilize newer and more advanced RepRap slicing and control software, since original Fab@home software relies on .Fab files (developed by Fab@home), instead of standard gcode. This conversion would not only allow the use of newer and more advanced gcode slicing and control software, but would also allow use to easily integrate the use of the Fab@home system into the Penn State EDSGN course.
  • Electronics: RAMPS_1.4 would be the easiest switch since it allows for max and min endstops. Differences between our current RAMPS_1.4 configuration and one used on a Fab@home would be:
1. The use of only two end stop pins(3 are needed with Opto endstops)
2. The use of only one set of Z-Axis stepper pins.
  • Firmware: Marlin would be the wisest pick for the same reasons it was choosen for the Mondo and Unit Clear Ramps based printers. Uniformity between machines would a highly desirable byproduct as well. Changes needed to adapt to Marlin firmware would be:
1. Change the endstop settings from optos to mechanical.
2. Check to make sure inactive endstop code is 1 instead of 0.
3. Change esteps/mm to that of the lead screws utilized by the Fab@home.
.

Extrusion

  • Utilize syinge extrusion tool (cholocate, silicon, UV material)
  • Develope and print L-bracket carriage adapter for Wade's Extruder. This would allow PSU RUG to utilize the machine's precision linear movement for prints requiring higher tolerances.

Reference